Electronic structures of heterometallic complexes [Ru(NO)(NO 2 ) 4 (OH)ZnL n ] according to the data of quantum-chemical calculations and photoelectron spectroscopy

A new complex [Ru(NO)(NO2)4(OH)Zn(PyO)2(H2O)](PyO is pyridine-N-oxide) is synthesized and structurally characterized. The new complex has the face coordination of the [Ru(NO)(NO2)4(OH)]2− anion to the Zn2+ cation similar to that in the earlier obtained complexes with other organic ligands. The methods of quantum chemistry and photoelectron spectroscopy show that the electronic structures of the [Ru(NO)(NO2)4(OH)ZnL n ] heterometallic complexes depend weakly on the nature of the ligands (L = Ph3PO, C5H5N, and C5H5N-O) coordinated to Zn2+ and are primarily determined by the electron density redistribution from the terminal nitro and nitroso groups of the ruthenium fragment to the zinc atom. The maximum change in the charge related to the nitroso group correlates with the strongest change in the energy of the occupied molecular orbital (HOMO-2 of the anion) oriented along the NO-Ru-OH coordinate.